Anki Sync Server vs Memo vs OmniGet: Self-Hosted Spaced Repetition Systems

Spaced repetition is one of the most scientifically validated methods for long-term knowledge retention. By scheduling reviews at increasing intervals, spaced repetition systems (SRS) ensure you study material just before you are about to forget it – maximizing retention while minimizing study time.

Cloud-based flashcard services like Quizlet and AnkiWeb lock your decks behind proprietary accounts and may discontinue features at any time. Self-hosting your spaced repetition system gives you permanent access to your knowledge base, complete privacy, and the ability to customize the scheduling algorithm. For a broader perspective on managing your personal knowledge, see our note-taking guide and knowledge base comparison.

In this guide, we compare three open-source approaches to self-hosted spaced repetition: Anki with a self-hosted sync server for the largest ecosystem, Memo for developers who want a terminal-first experience, and OmniGet for comprehensive course and book-based learning.

Understanding Spaced Repetition

Spaced repetition is based on the “forgetting curve” discovered by Hermann Ebbinghaus in 1885. The core insight is that each time you successfully recall information, the memory becomes stronger and the interval before the next review can be extended. Modern SRS software uses algorithms to calculate optimal review intervals:

• SM-2: The original algorithm used by SuperMemo and Anki. Simple but effective.
• FSRS: A newer, machine-learning-based algorithm that adapts to individual learning patterns. Now supported as an alternative scheduler in Anki.
• Leitner System: A physical box-based approach where cards move between compartments based on recall success.

Anki + Self-Hosted Sync Server

Anki is the most widely used spaced repetition software in the world, with over 27,000 GitHub stars. It uses the SM-2 algorithm (and now supports FSRS) and has the largest shared deck ecosystem – over 80,000 community-created decks covering languages, medicine, law, programming, and more.

By default, Anki syncs via AnkiWeb, a free cloud service. However, you can replace AnkiWeb with a self-hosted sync server to keep all your flashcard data on your own infrastructure.

Key Features

• Massive deck library: Access to tens of thousands of shared decks via AnkiWeb (the desktop client works with self-hosted sync too).
• Rich media support: Images, audio, LaTeX, video, and custom HTML/CSS in cards.
• FSRS algorithm: Next-generation scheduling that adapts to your performance.
• Cross-platform clients: Desktop (Windows, macOS, Linux), Android (AnkiDroid), iOS (AnkiMobile), and web.
• Add-on ecosystem: Over 1,000 community add-ons for gamification, heatmaps, and custom study modes.

Self-Hosted Sync Server Setup

The Anki Sync Server replaces AnkiWeb with your own server. This is particularly useful for teams, organizations, or anyone who wants full data sovereignty.

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# Install the sync server via pip
pip install ankisyncd

# Create a configuration file
mkdir -p ~/.anki-sync-server
cat > ~/.anki-sync-server/ankisyncd.conf << CONF
[server]
host = 0.0.0.0
port = 27701
data_root = ~/.anki-sync-server/data
base_url = /
auth_db = ~/.anki-sync-server/auth.db
CONF

# Start the server
python -m ankisyncd

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services:
  anki-sync-server:
    image: docker.io/linuxserver/anki-sync-server:latest
    container_name: anki-sync-server
    restart: unless-stopped
    ports:
      - "27701:27701"
    volumes:
      - anki-sync-data:/config
      - /etc/localtime:/etc/localtime:ro
    environment:
      - PUID=1000
      - PGID=1000
      - TZ=UTC

volumes:
  anki-sync-data:
    driver: local

After starting the sync server, configure your Anki desktop client to point to http://your-server:27701/ instead of AnkiWeb. Go to Tools > Preferences > Network and set the custom sync server URL.

Memo: Terminal-First Spaced Repetition for Developers

Memo is an open-source spaced repetition application designed specifically for programmers and technical learners. With nearly 1,900 stars, it takes a minimalist, terminal-oriented approach to flashcard learning.

Key Features

• Terminal-native: Runs entirely in your terminal – perfect for developers who live in the command line.
• Code-focused: Designed for memorizing syntax, algorithms, API references, and technical concepts.
• Lightweight: Single binary with no external dependencies or database requirements.
• Markdown-based cards: Write flashcards in simple Markdown files, version-controllable with Git.
• No-frills SRS: Implements a straightforward spaced repetition schedule without gamification.

Installation and Usage

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# Install from source (requires Go)
git clone https://github.com/olmps/memo.git
cd memo
go build -o memo ./cmd/memo
sudo mv memo /usr/local/bin/

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# Create a flashcard deck
mkdir -p ~/.memo/decks
cat > ~/.memo/decks/go-syntax.md << DECK
# Go Syntax

Q: What is the zero value of a string in Go?
A: "" (empty string)

Q: How do you create a buffered channel?
A: make(chan Type, bufferSize)

Q: What does `defer` do?
A: Schedules a function call to be run after the surrounding function returns
DECK

# Start studying
memo study go-syntax

Memo is best suited for developers who want a no-nonsense, keyboard-driven study experience. It integrates naturally with your existing dotfiles and Git workflow – your flashcard decks are just text files.

OmniGet: Course and Book-Based Learning Platform

OmniGet is a desktop application designed for studying online courses and books systematically. With over 2,200 stars, it bridges the gap between passive content consumption and active recall practice.

Key Features

• Content ingestion: Import content from online courses, textbooks, and PDFs directly into the app.
• Auto-flashcard generation: Extracts key concepts and generates flashcards from your study materials.
• Spaced repetition scheduler: Built-in SRS algorithm for scheduling reviews.
• Progress tracking: Visual dashboards showing study progress, retention rates, and knowledge gaps.
• Cross-platform: Desktop application for Windows, macOS, and Linux.

Installation

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# Download the latest release
wget https://github.com/tonhowtf/omniget/releases/latest/download/omniget-linux-x86_64.AppImage
chmod +x omniget-linux-x86_64.AppImage
./omniget-linux-x86_64.AppImage

OmniGet is ideal for students and self-learners who work through structured courses and want to convert passive reading into active recall practice. The auto-generation feature saves time compared to manually writing every flashcard. For multi-user educational environments, our JupyterHub guide covers self-hosted notebook platforms that pair well with structured course study.

Comparison Table

When to Use Each Tool

Anki + Self-Hosted Sync Server

Choose Anki when you want the most mature, feature-rich spaced repetition system available. It is the gold standard for language learners, medical students, and anyone who benefits from a large deck ecosystem. Self-hosting the sync server gives you data privacy without sacrificing the ability to sync across devices.

The shared deck library alone is a massive advantage – you can download pre-built decks for almost any subject and start studying immediately. The FSRS algorithm integration provides modern, adaptive scheduling that outperforms the traditional SM-2 approach.

Memo

Choose Memo when you are a developer who wants a lightweight, terminal-native study tool. It is perfect for memorizing programming language syntax, framework APIs, or algorithm patterns. The Markdown-based card format means your decks live alongside your code and dotfiles – fully version-controllable with Git.

Memo is not competitive with Anki in terms of features, but it excels at being simple, fast, and keyboard-driven. If you already spend most of your time in a terminal and want to study without switching contexts, Memo is an excellent choice.

OmniGet

Choose OmniGet when you are working through structured courses or textbooks and want to convert passive content into active recall practice. The auto-flashcard generation feature is the key differentiator – instead of manually writing hundreds of cards, you import your course material and let the tool extract key concepts.

This is particularly useful for online courses, certification prep, and textbook study. The progress tracking dashboards help you identify knowledge gaps and focus your review sessions on the weakest areas.

FAQ

Is self-hosting Anki sync server difficult to set up?

Not at all. The sync server is a lightweight Python application that runs on any machine. With the Docker Compose setup provided above, you can have a sync server running in under five minutes. Configuration involves setting the server URL in your Anki client – no complex networking or database setup required.

Can I use the self-hosted Anki sync server with AnkiDroid on Android?

Yes. AnkiDroid supports custom sync server URLs. Go to Settings > Advanced > Custom sync server and enter your self-hosted server URL. This allows you to study on your Android phone while keeping all data on your own infrastructure.

Does Memo support image or audio flashcards?

No. Memo is designed as a text-only, terminal-native application. It focuses on memorizing code syntax, technical concepts, and text-based information. If you need multimedia flashcards (images, audio pronunciations, LaTeX formulas), Anki is the better choice.

Can I export my Anki decks if I want to switch to a different tool?

Yes. Anki supports exporting decks in several formats including .apkg (Anki package), CSV, and plain text. The exported data can be imported into other SRS applications or used as a backup. Your self-hosted sync server stores data in SQLite, which can also be exported directly.

How does the FSRS algorithm compare to the traditional SM-2?

FSRS (Free Spaced Repetition Scheduler) uses machine learning to optimize review intervals based on your individual performance history. In studies, FSRS typically reduces total review time by 20-30% while maintaining or improving retention rates compared to SM-2. Anki now supports FSRS as an opt-in scheduler – you can switch in Preferences > Scheduling.

Is OmniGet suitable for team learning or classroom use?

OmniGet is primarily designed for individual study. It does not have built-in multi-user support or shared deck functionality. For team or classroom learning, Anki with a self-hosted sync server is a better choice, as it supports multiple user accounts and can share decks through the server.

How do I back up my self-hosted Anki sync server data?

The sync server stores all data in a SQLite database and file directory (configured via data_root in the config file). Back up both the database file and the data directory. If using Docker, back up the named volume: docker run --rm -v anki-sync-data:/data -v $(pwd):/backup alpine tar czf /backup/anki-sync-backup.tar.gz /data.